In reply to timnoldy:
I’ve just done this for my son in his new house. There will be studs in a non-load bearing wall, but it’s not unknown for there not to be any verticals above the door opening except for the door frame supports which would be around 30+ inches apart.
Two solutions.
You’ll be mounting the beastmaker on board. Fit the board directly above the door frame architrave to take the main force, and secure with plasterboard fixings. Not ideal, but is usually ok.
Paul Crusher makes a series of fingerboard mounts which fit into the top of the doorframe and work well. If you search for Crusher holds fingerboard mount you’ll find his online shop